The present application is directed to a grain spreader for evenly distributing grain or the like within a storage bin and, in particular, to such a spreader that provides for even spread of grain with respect to annular rings within the bin, as well as even distribution along each annular ring. The spreader also allows correction of nonuniform regions within the bin that are caused by nonuniform drying of the grain entering the bin or the like.
Grain is normally conveyed into the top of the storage bin during the bin filling process. Because the grain has an angle of repose, if the grains is not spread, it normally tries to mound beneath the delivery point. If this is allowed to occur, the bin will fill all of the way to the grain inlet above the mound leaving large portions of the bin unfilled. In the early days of a grain storage in such bins, farmers had to actually enter the bin and shovel the grain to a uniform level. Later, there were many attempts made to provide a spreader that operably distributed the grain in a manner to try to level the top of the grain. Such spreaders met with varying degrees of success. However, even a very good spreader is often plagued by grain having varying degrees of wetness or the like, such that it does not deposit evenly within the bin. In such situations it is still necessary to be able to make some adjustments to the distribution of incoming grain to fill one or more concentric annular rings having vertical axes within the bin or sections of rings within a partially filled bin.
In order to perfectly fill a bin, it would be necessary to have perfectly uniform grain and to impart to each particle of grain a continuously varying momentum or velocity that varies infinitely during filling and projects the particles in continuously rotating arcs over the radius of the bin. In practice it is not possible to provide a constantly changing and infinitely variable momentum to the particles of grain. However, it is desirable to provide a spreader pan having variable length vanes that are sized in accordance with a formula intended to impart velocities to the grain that produce generally uniform concentric rings within the bin, where the level of such grain becomes increasingly more uniform as the number of vanes increases.
In certain instances it is desirable to have the spreader pan be balanced by vanes of equal length or by providing a pattern of non equal length vanes that balances the spreader pan as much as possible.